Bag and method of making the same



Filed 00tll, 1947 2 Sheets-Sheet 1 lo FIG. I

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Feb. '7, 1950 E. s. KARDoN 2,496,796

BAG AND METHOD OF MAKING THE SAME INVENTOR. EMANUEL s. KARDON ATTORNEY.

Feb. 7, 1950 v E. s. KARDON 2,496,796

BAG AND METHOD OF MAKING THE SAME Filed Oct. 11, 1947 2 Sheets-Sheet 2 FIG. 5

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INVENTOR. EMANUEL S. KARDON Patented Feb. 7, 1950 UNl'lED STATES PATENT OFFICE BAG AND METHOD or MAKING Tan SAME Emanuel s. Kardon, Melrooe Park, Pa.

Application October 11, 1947, Serial No. 779,251

2 Claims. (Cl. 229-59) This invention relates to bags and a method of making the same, and it relates more particularly to the formation of the bottom of a ba made of paper or the like, of the automatic or self-opening satchel bottom type.

More specifically considered, the invention relates to a bag of the aforesaid type having an inner lining of impervious material of the kind whereby an effective seal may be made at certain places, preferably by the application of heat.

The principal object of the present invention is to provide a paper bag having the bottom thereof formed in a novel manner whereby the same will be effectively sealed.

A further object of the invention is to provide a bag of the inner lined type and a method of making the same, whereby the bottom of the bag will be effectively sealed against leakage, so that the contents of said bag will be maintained in good condition without loss or deterioration by reason of sifting or breathing through breaks or openings in the seal.

It is a further object of the present invention to provide a bag of the character aforesaid which may be made on automatic bag making'machines, with but slight changes in said machines.

The nature and characteristic features of the present invention will be more readily understood from the following description, taken in connection with the accompanying drawings forming part hereof, in which:

Figure l is a perspective view illustrating a form of tube from which a bag embodying the present invention may be made according to the method of the invention;

Fig. 2 is a plan view of the tube structure shown in Fig. 1, but looking at the underneath face threof after the same has been slitted in a manner peculiar to this invention;

Fig. 3 is a plan view illustrating an intermediate step in the formation of the bottom of the ba Fig. 4 is a similar view illustrating a later step in the formation of the bottom of the bag;

Fig. 5 is a similar view illustrating a still later step in the formation of the bottom of the bag;

Fig. 6 is a similar view illustrating the bottom of the bag in its completed form;

Fig. '7 is an enlarged cross-section taken approximately on the line 1-1 of Fig. 3;

Fig. 3 is a view similar to Fig. 7 taken approximately on the line 8-8 of Fig. 4; and

Fig. 9 is a perspective view further illustrating the formation of the bottom of the bag at the stage shown in Fig. 3 of the drawings.

It should of course be understood that the description and drawings herein are illustrative merely, and that various changes and modificacations may be made in the bag structure disclosed, and in the several steps in the formation of the bottom thereof, without departing from the spirit of the invention.

Referring to the drawings, in the particular embodiment of the invention therein shown, I0 is the outer sheet of the bag, preferably made of paper or other suitable material of requisite strength, and II is the inner lining of the bag, preferably made of a sheet of material impervious to the passage of air, vapor, or moisture, but which is suillciently fusible, upon the application of heat to cause the abutting faces to adhere to each other to provide a seal. However, if desired, the inner lining may comprise a layer of suitable material applied directly to the inner face of the paper of which the outer sheet of the bag is made.

The inner lining H is preferably made of a separate sheet of heat scalable material which may in itself be thermo-plastic, or the surface of said inner liner sheet may be coated with thermo-plastic material, so as to cause the abutting faces of said material to adhere to each other upon the application of heat at the desired places during the formation of the bag.

Of course, if desired, the seal of the inner lining may be obtained by the use of suitable adhesive applied at the desired places to cause the faces of the inner liner to adhere to each other at such places.

The outer sheet of the bag with the inner liner sheet disposed adjacent thereto is first formed in a tube of the bellows fold type, as illustrated in Fig. 1 of the drawings, this being done in the usual manner on one of the automatic bag machines which are available for such purpose.

At the end of the tube which is to form the bottom of the bag cuts l2 and I3 are made, which cuts extend through the outer sheet of the bag structure, as well as the portion of the inner liner contiguous thereto, these cuts, however, being made on one wall only of the tube thereby providing on one face a double ply tab portion H.

The portion of the tube which is to form the bottom of the bag is then formed into a diamond fold, as illustrated in Figs. 3, '7 and 9 of the drawings, which will differ from the diamond fold usually employed in the making of satchel bottom bags in that a tab portion I4 is provided at one end only of the diamond fold, and also in that in the center there are provided upwardly ex- 3 tending flaps II the outer face portions of which are of the paper or the like of which the outer sheet of the bag is made, having sandwiched therebetween two thicknesses of the heat sealable material ll disposed face to face.

It will be noted that at the apex of the inner triangle of the diamond fold, where the upwardly extending flaps terminate, said flaps II will be united to each other by a vertical fold or crease It so that no opening will occur at this location when the sealing is effected as hereinafter set forth.

While the bag bottom being formed is in the stage shown in Figs.- 3 and 9 of the drawings, heat is applied to the side faces of the upwardly extending flaps it, which heat should be of a suilicient degree to penetrate and cause the abutting inside faces of the portions of inner liner within the flaps I! to adhere to each other and to provide a seal the entire length thereof.

The flaps I! are then folded down, as shown in Pig. 4 of the drawings, to lie flat and parallel to the plane of the formed portion of the bag bottom.

While the bag bottom is in the condition shown in Fig. 4 of the drawings, heat is applied across the protruding portion I I of the bag bottom along the transverse line I 8 which should be located between the tab portion l1 and the crease line ll (see Fig. 5), upon which the final fold of the bottom portion will be made. The triangular portion of the diamond folded bottom is now bent over, as illustrated in Fig. 5 of the drawings, along the crease line 2| after which the portion II, with the tab it extending therefrom, is folded over along the crease line It to complete the formation of the bottom, as illustrated in Fig. 6 of the drawings.

The tab portion It is caused to adhere to the bottom of the bag by applying suitable adhesive between the contiguous faces of the tab portion It and the triangular portion 2| of the bag bottom structure. 7

It will be seen that a bag constructed as aforesaid will have the bottom portion effectively closed and sealed, not only to prevent any shifting of finely powdered contents through the bottom, but also to prevent any ingress or egress of air or vapor which might tend to deteriorate the contents of the bag when the same is filled.

It will, of course, be understood that the invention is applicable to unlined bags, as well as those having an inner lining, and also, where an inner lining'is used, the same be of heat fusible material, or of other material, it being necessary, when materials are used which are not heat fusible, to apply a suitable adhesive at the proper places, to cause the abutting faces to adhere to each other at such places.

1. A rectangular bottom bag formed of a flattened tube having front and rear walls and initially having a pair of spaced longitudinal slits in one of said walls only at the end of the tube from which the bottom of the bag is formed thereby providing a single bottom-tab, the slits extending inwardly from the edge and spaced '4 from the sides, the bottom being formed by a partial diamond fold with the aforesaid tab at one end only thereof and the other end being shaped into a triangle terminating in an apex, flaps at the middle of the diamond fold having a seal therebetween along a longitudinal line extending the full length thereof substantially medially of the partial diamond fold, said flaps being united by a crease line at the apex end of the triangle, said flaps being folded down against a portion of the bottom, adjacent faces of the portion of the bottom adjacent the tab having a seal therebetween extending entirely across along a transverse line, the triangular portion being folded over to form a portion of the bottom, and the portion carrying the tab being folded to extend over the apex of the triangular portion and sealed to said triangular portion to complete the bottom.

2. A self-opening rectangular bottom bag formed of a flattened tube made of an external sheet of paper or the like and having an inner lining of heat sealable material, said bag having bellows folds at the sides and having front and rear walls and initially having a pair of spaced longitudinal slits in one wall only of the end portion of the tube from which the bottom of the bag is formed to form a single bottom tab, the slits extending inwardly from the edge and being spaced from the sides, the bottom being formed by a partial diamond fold with the aforesaid tab at one end only thereof and the other end thereof being shaped into a triangle terminating in an apex, flaps at the middle of the partial diamond tab sealed to each other along a longitudinal line substantially medially of the partial diamond fold, said flaps being folded down against a portion of the bottom, adjacent faces of the portion of the bottom adjacent the tab being sealed to each other along a transverse line extending across the bottom, the triangular fold being folded over to form a portion of the bottom, and the portion carrying the tab being folded over and overlapping the triangular portion and sedared to said triangular portion to complete the bottom, the various parts which constitute the bottom structure comprising corresponding portions of the external sheet and the inner line formed and folded together in unison.

EMANUEL S. KARDON.

REFERENCES CITED The following references are of record in the flle of this patent:

I UNITED STATES PATENTS Number 

